<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>位置3_外部样式</title>
    <link rel="stylesheet" href="./position3.css">
</head>
<body>
<h1>欢迎来到上海</h1>
<h2>欢迎来到北京</h2>
<p>这是内容</p>
</body>
</html>